Fleischer D, Espiner E A, Yandle T G, Livesey J H, Billings J, Town I, Richards A M
Department of Endocrinology, Christchurch School of Medicine and Radiology, Christchurch Hospital.
N Z Med J. 1997 Mar 14;110(1039):71-4.
Recognition of heart failure may be difficult in patients presenting with acute dyspnoea, particularly in the presence of chronic airways obstruction or obesity. In a previous study of patients with acute dyspnoea, we showed that the measurement of plasma brain natriuretic peptide (BNP)-a hormone secreted in increased amounts by the failing heart-accurately distinguishes heart failure from primary lung disorder. The aim of the present study was to develop a rapid assay for BNP and evaluate its diagnostic use in patients acutely hospitalised for increasing dyspnoea of any cause.
A rapid assay for plasma BNP, providing results within 24 h of blood collection, was developed without loss of precision. The results of the rapid and previously established BNP assays were highly correlated (r = 0.9). To determine the diagnostic value of the rapid assay, measurements were undertaken on the day of admission in 123 breathless patients (mean age 68.3, range 23 to 90 years) and related to conventional diagnostic assessments and final outcome.
In patients diagnosed and treated urgently for clinical heart failure, plasma BNP was significantly higher (115 (SE 13) pmol/L, n = 39) than in those without clinical heart failure (33 (5) pmol/L, n = 84, p < 0.001). Using a cut-off of 50 pmol/L for the presence of heart failure, there was discordance between BNP level and clinical diagnosis in 21 of 123 cases. Reassessment after independent analysis of discordant cases increased the difference in BNP level in the presence (123 (13) pmol/L, n = 43) or absence (24 (1.5) pmol/L, n = 80) of heart failure. Using two way analysis of variance, no further improvement in discrimination was found when chest radiographs were used together with the BNP data.
Rapid BNP assays are practicable and provide accurate information on cardiac status-superior to chest radiographs in many cases-early in the course of the patient's presentation with acute dyspnoea.
对于急性呼吸困难患者，尤其是合并慢性气道阻塞或肥胖的患者，心力衰竭的诊断可能存在困难。在先前一项针对急性呼吸困难患者的研究中，我们发现，检测血浆脑钠肽（BNP）——一种由衰竭心脏分泌量增加的激素——能够准确区分心力衰竭与原发性肺部疾病。本研究的目的是开发一种快速检测BNP的方法，并评估其在因任何原因导致呼吸困难而急性住院患者中的诊断应用价值。
开发了一种血浆BNP快速检测方法，在采血后24小时内得出结果，且不损失检测精度。快速检测方法与先前建立的BNP检测方法的结果高度相关（r = 0.9）。为确定快速检测方法的诊断价值，对123例呼吸困难患者（平均年龄68.3岁，范围23至90岁）入院当天进行检测，并将结果与传统诊断评估及最终结局相关联。
在因临床心力衰竭而接受紧急诊断和治疗的患者中，血浆BNP水平显著高于无临床心力衰竭的患者（115（标准误13）pmol/L，n = 39）（33（5）pmol/L，n = 84，p < 0.001）。以50 pmol/L作为心力衰竭存在与否的临界值，123例患者中有21例BNP水平与临床诊断不一致。对不一致病例进行独立分析后重新评估，发现存在心力衰竭（123（13）pmol/L，n = 43）或不存在心力衰竭（24（1.5）pmol/L，n = 80）时BNP水平差异增大。使用双向方差分析，当胸部X线片与BNP数据一起使用时，未发现鉴别能力有进一步提高。
快速BNP检测方法切实可行，能在患者急性呼吸困难病程早期提供有关心脏状况的准确信息——在许多情况下优于胸部X线片。
